The Air Force plans to save $3.5 billion over the next five years by retiring all A-10s, like this one shown in southern Iraq. (Alan Lessig/staff)

Chief of Staff Gen. Mark Welsh and Air Force Secretary Deborah Lee James on Wednesday defended plans to scrap the A-10 fleet and retire roughly 40 C-130s to skeptical lawmakers who cautioned against making radical force structure changes too quickly.

“I understand, General Welsh, the dilemma you face, I mean you didn’t pass sequestration, we did,” said Sen. Lindsey Graham, R-S.C. “[But I still] believe the A-10 is unique,” he said.

The Air Force said it needs to retire the A-10 because it’s a single mission aircraft. Service officials say they would achieve more savings by retiring a full fleet of aircraft versus more aircraft over multiple fleets.

Congressional leaders favor the A-10 because it is cheaper to operate than high-performance fighter jets. The A-10 has also been the work horse for close-air support for ground troops in Afghanistan and Iraq.

However, the Pentagon does not envision fighting long-term ground wars in its future, and would rather use multi-mission aircraft that could additionally provide close-air support.

Graham and Sen. Dick Durbin, D-Ill., suggested the Air Force has more work ahead to convince Congress that retiring the A-10 is a smart move.

“So for about $3.5 billion over the next five years, if [Congress] could find the money, could you afford to keep the A-10 on board?” Graham said.

Welsh said money wasn’t the only problem.

“The issue is what Air Force do you want at the end of sequestration?” Welsh said “We have other airplanes that can do close-air support, and...pilots from those systems will help populate other systems like the emerging F-35 squadron.”

Welsh and other Air Force leaders have said the F-35 joint-strike fighter, expected to be operational in 2021, will be able to fill the close-air support mission now assigned to the A-10.

But the F-35 will only be operational in 2021, “if all goes well,” Graham reminded Welsh.

The Defense Department said that software problems are the largest problem facing the F-35 program, which could delay the delivery of its operational capabilities.

“It’s hard to use a squadron that doesn’t exist, and A-10s exist, while F-35s are not around,” Graham said.

Lawmakers also pressed Welsh and James to explain the rationale for moving and retiring C-130s. Sen. Thad Cochran, R-Miss., asked why the Air Force plans to move 10 C-130J transport planes from a base in his home state — Keesler Air Force Base — to Little Rock Air Force Base, Ark.

“I’m concerned about the justifications that we find in the total Air Force plan for 2015, including in the proposal is the indication there will be a relocation of 10 C-130Js from Keesler Air Force Base to some other location, which seems to be inconsistent with comments we’ve had in the past…[and] we haven’t heard any real justification for this decision,” Cochran said.

Gen. Jackson, Chief of Air Force Reserve, said Little Rock Air Force Base, with its two active-duty squadrons, reserve squadron and training schools for the C-130H and C-130J aircraft, is the best place to consolidate as the C-130 fleet gets smaller.

The budget reflects that the Reserve has reduced its C-130 fleet by nearly 40 percent — from 104 to 66 planes — over the last five years.

The Air Force plans to move about a dozen of the older C-130Hs from Little Rock in 2015, a year after the base receives newer C-130Js.

“We just have too many C-130s in the inventory,” James said. The goal is to try to keep new C-130s in the inventory, James said, while consolidating and retiring the old aircraft.

Jackson also assured Cochran that the C-130s used for the Hurricane Hunters mission out of Keesler were not at risk of being relocated.

“There’s absolutely no intention of removing the 403rd Wing or the Hurricane Hunters mission from Keesler,” Jackson said. “There are currently 10 C130Js that remain with the 403rd Wing, and the other 10 C-130Js that the Reserve has assigned to them are the ones we’d be looking to move to Little Rock to achieve the synergy and savings we want to achieve,” Jackson said.